The Dissolution Characteristics of Chrysocolla in NH₃ -(NH₄)₂ CO₃ Solutions

Abstract

Chrysocolla samples were leached in ammonia-ammonium carbonate solutions of 0.25 to 6.00 M concentrate total ammonia  at a temperature range of 25 °c to 55 °C. The leaching curves for the fraction extracted,  , as a function of time follow the expression: α = logₑ (βδ t+l)/β which is the integrated form of the exponential rate law, assuming a linear dependence of the free energy of activation with the fraction extracted. The initial kinetics follow the Langmuir-Hinshelwood relation: rate = a (NH +/4) / (1 +b (NH+/4) ) which is indicative of and adsorption process preceding chemical reaction